# Meter Circuit

#### terrytapp

Joined Mar 30, 2006
15
Design a meter circuit that will read a battery voltage in a started and running car:

I am a female who doesn't even check her dip stick to see if its oiled!
And my electronics math instructor wants me a answer a question such as this! HA!
Any help would be appreciated.... Thanks a bunch!
Terry

** forgot the "R" in electronics in the subject field. I can't design a meter circuit or edit a post in this forum, but I can spell! **

#### paultwang

Joined Mar 8, 2006
80
Originally posted by terrytapp@Mar 30 2006, 03:44 AM
Design a meter circuit that will read a battery voltage in a started and running car:
[post=15621]Quoted post[/post]​
I don't know the difference between the measurement of battery voltage in a running car and a non-running car? DC Voltage is DC voltage to me. I guess you want to measure the loaded voltage (because no-load voltage of a car battery is higher than the stated value).

Have you read the Voltmeter design?

#### JoeJester

Joined Apr 26, 2005
4,390
Paul,

I believe the instructor's intent is for the student to understand there are two voltage levels on a car battery. One when the car is not running and one when it is running.

When building the voltmeter, one must consider what they are measuring.

Terry,

If you have questions after reviewing the link that Paul posted, feel free to post them.

#### beenthere

Joined Apr 20, 2004
15,819
Hi,

As long as we're guessing.... The statement says "started and running car". To me that implies a meter that indicates a narrow range of voltage in an expanded scale, enabling the instrument ot indicate if the charging system was keeping up with demand. You don't care about voltages below 10 or above 14 because those are alarm points indicating failures.

Which leads to a prediction: The next post will have another possible interpretation and solution, and that none will match the instructor's intent.

We're trying, TT

#### terrytapp

Joined Mar 30, 2006
15
paultwang; Have you read the Voltmeter design?

Paul.
Yes, I have read the voltmeter design, that is how I found this wonderful forum! (smiles)
I was wanting more then what I read in 'All About Circuits-Voltmeters'
I was in class all day and reluctently turned in my paper.
We will see how it goes.
Thanks to all of you who replied to my question.
You Guys Rock!
Terry